Hypertrophic obstructive cardiomyopathy and infective endocarditis: a report of seven cases and a review of the literature.

Seven cases of infective endocarditis (IE) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are presented in this report. The previous literature is critically reviewed, and the following points are discussed: (a) IE complicates HOCM in 5-9% of cases; (b) anatomical and haemodynamic alterations of HOCM cause microtraumas on heart valves and the endocardium; the resulting endocardial lesions represent sites for bacterial seeding as well as other congenital or acquired heart disease; (c) prognosis is worse in patients with IE associated with HOCM than in patients with IE alone or associated with congenital heart disease; (d) the most frequently isolated organisms are saprophytes; (e) most patients were exposed to bacteraemias before the onset of IE.